Regarding the use of user isolation technology in a WLAN networking environment, which of the following statements is false?

Regarding the use of user isolation technology in a WLAN networking environment, which of the following statements is false?
A . User isolation between groups means that users in different groups cannot communicate, but internal users in the same group can communicate
B . Isolation within a user group means that users within the same group cannot communicate with each other
C . The user isolation function means that the Layer 2 packets between all wireless users associated with the same AP cannot be forwarded to each other
D . Intra-group isolation and inter-group isolation cannot be used at the same time

Answer: D